Bernese Mountain Dog

The Bernese Mountain Dog (known in German as the Berner Sennenhund or Dürrbächler) is a large breed that comes from the Swiss Alps and the canton of Bern. It belongs to a group of four Sennenhund-type dogs, and its ancestry traces back to Roman mastiffs. The name "Bernese" points to its origin in the Bern region, while "Sennenhund" combines the German words for "alpine pasture" and "dog," reflecting its role alongside alpine herders and dairymen called Senne. Historically, these dogs worked as all-purpose farm animals, pulling carts as draft dogs. The breed gained official recognition in 1912.

In some areas, the breed was once called the Dürrbachhund or Dürrbächler, after the small town of Dürrbach where these large dogs were especially common. Their roots lie in Roman mastiffs. Farmers used them to guard property, drive dairy cattle long distances to alpine pastures, and pull carts loaded with milk and cheese—earning them the local nickname "Cheese Dogs." In the early 1900s, enthusiasts began showing a few examples at Bern dog shows, and in 1907, breeders from the Burgdorf area founded the first breed club, the Schweizerischer Dürrbach-Klub, which wrote the first breed standard. By 1910, there were 107 registered members. A 1905 photo shows a working Bernese Mountain Dog at the Fumee Fall rest area in Quinnesec, Michigan. The American Kennel Club recognized the breed in 1937, classifying it in the Working Group. In the US, its popularity has grown, ranking 19th among AKC breeds in 2024. In German-speaking countries, it is a common family dog; the German Association of Dog Breeders ranked it 11th by live births in 2014.

Like other Sennenhunde, the Bernese Mountain Dog is large and heavy, with a distinctive tri-colored coat: black with a white chest and rust markings above the eyes, on the sides of the mouth, the front of the legs, and around the white chest. It is the only long-coated Sennenhund breed. An ideal marking pattern gives the impression of a white horseshoe around the nose, which is always black. A white "Swiss cross" appears on the chest from the front, and a "Swiss kiss" is a white mark often found behind the neck, though a full ring around the neck does not meet the standard. The AKC standard disqualifies blue eye color and any ground color other than black. Males stand about 64–70 cm at the withers, with an ideal range of 66–68 cm; females stand 58–66 cm, ideally 60–63 cm. Weights range from 35–55 kg for males and 35–45 kg for females.

This breed is dry-mouthed, slightly longer than tall, and highly muscular, with a strong, wide back. The head is flat on top with a moderate stop; ears are medium-sized, triangular, set high, and rounded at the tips. Teeth meet in a scissors bite. Legs are straight and strong, with round, arched toes. Rear dewclaws are often removed. The bushy tail is carried low.

Health issues are significant. Cancer is a major concern: one study found 55% of deaths due to neoplasia. Elbow dysplasia is common, with prevalence ranging from 13.91% to 26%. An allele of the SOD1 gene (SOD1:c.52T) has been found only in this breed, affecting 3.5% of dogs, and is linked to canine degenerative myelopathy; another mutation for the same condition has a 38% prevalence. Immune-mediated glomerulonephritis is more frequent, and a Swiss study found both incidence and mortality from renal disease to be 3.2 and 8.2 times the average, respectively. High-grade mastocytoma risk is elevated, with an Austrian study showing Bernese Mountain Dogs three times more likely to develop it. Histiocytosis—a group of disorders involving histiocyte buildup—is also prevalent; malignant histiocytosis accounts for a quarter of all tumors in the breed and has a heritability of 0.298. Mutations in tumor-suppressing genes (CDKN2A/B, PTEN, RB1) and the PTPN11 gene are believed to play a role. The breed is also commonly affected by type I von Willebrand's disease.

Life expectancy is low even for a large breed. A 2016 Swiss study of 389 dogs reported an average lifespan of 8.4 years, and a 2013 Dutch study found 8 years.